Wave translating method and circuits



3 1 3 2 5 2 caoss REFERENCE SEARCH 3002.1

July 26, 1938. J. FEARING "AVE TRANSLATING METHOD AND CIRCUI'i'S Filed NOV. 13, 1935 13 2 4 an a 83 4 1a Patented July 26, 1938 UNITED STATES PATENT OFFICE ems-is wave msnsmmo mnop m cmcms suun L Fearing. sea-mic; N. r. Application Hovemher 18. st. Serial No. 11am Ola-lull.

This invention relates to methods of translating electrical energy into impulses or alternating current and to apparatus and circuitsemployed 10 small range of frequencies can be produced while using a given frequency determining standard. such as a resonant circuit. When frequencies above that range are to be produced, it is necessary to substitute a different frequency deter- 15 mining standard in the circuit or to resort to cascade harmonic producers. A cascade harmonic producer ordinarily requires one or more tuned circuits in addition to that for the fundamental frequency. It also sliflers the limitation that when a sine wave of frequency, 1. is subjected to a single harmonic producing operation, the harmonic components of frequencies 2], 3). and higher frequency, are of much smaller amplitude than that of the fundamental frequency I. Fur- 23 thermore, the harmonic components of progressively higher frequency are of successively smaller amplitude.

An object of the present invention is to simplify the production of impulses and alternating o currents of constant fundamental and harmonic frequency over a wide range of frequencies and to improve the efiiciency of production of such impulses and currents.

another object is to generate impulses or alterg5 nating currents over a wide range of frequencies under the control of a single frequency determining standard. and to produce very high frequency impulses and currents under the control of u a frequency standard of lower frequency.

Another object is to utilize a periodically defleeting beam of electric carriers to commutate electric current in a single operation at a frequency equal to or higher than that of the positive and negativepeaks in a wave controlling the 45 deflection of the beam. and to derive-the control wave fromthe deflecting beam.

Otherohiects'aretorestricttheproduotionofand'the am" tude of undesired harmonics. to

for the commutator.

(Oi. 250-86) commutator segments arranged and connected in such relation to the path that the discharge current may be simultaneously commutated at more than one frequency. The cyclic deflection of the beam may be maintained by waves derived from 5 the resulting impulses or from an independent source.

According to another feature. the beam may trace a cyciicpathin which lessthanallof one set of alternate segments are connected to one 10 output circuit for the production of current of the frequency which maintains the cyclic deflection of the beam while the-beam is at the same I time commuta'ting current at a different frequency for another output circuit.

According to another aspect of the present invention, the beam is deflected over any one of a plurality of rows of commutator segments to control the distribution of current impulses in the output circuit connections of the segments. The m number of segments in any row may be sufficient to make the commutation frequency many times that of the deflection frequency. Diflerent rows may contain difierent numbers of segments. and provision is made for selecting a deflection path over any desired rowto determine the output circult over which impulses are to be transmitted. or to determine the frequency of the impulses.

when the beam has a given deflection frequency. any one of a plurality of different output frew quencies may be produced, the output frequents in any case depending upon the deflection frequency and upon the effective number of se ments fnthe rowover which the beamis deilected. l'l' cncies in the range between the frequencies produced by different rows may be obtained by selecting harmonics produced within this range while the deflection frequency remains unchanged, or by adiusting the deflection fro-- quency to produce commutation or harmonics at thedesiled frequency.

These and other features of the invention will be understood from the following detailed descriptionin connection with the aco mpcnfl l drawing illustrating specific a iications of the 5 invention.

iis'adiagramof oneform ofs'pace discharge device and the circuit-thereof forproducingel trical impulses and alternating currents of fundamental and harmonic frequeuso ci'es. i

rlaflis aqiagrammlticradiaifaceviewofthe commutator of Fig. l. j

l'lg.8is a-radiaifaoeviewofasupportingdisl:

CROSS REFERENCE Fig.4isafragmentaryviewofanaxialsection of thecommutatorendof thespaoedischarge device of Fig. 1, showing in detail the arrangement for supporting the commutator and an axial sectionof the Pig. 8 disk, taken on the line 4-4 of Fig. 3.

Fig; is a diagram of circuit connections for the commutator of Figs. 1 and 2.

Figures 8 to are diagrams of modified forms of commutators and output connections.

Referring to Fig. i, the space discharge device I, consisting of a highly evacuated tube, preferably of transparent glass. contains the heater 2 for the cathode 3 which in turn is adapted when the tube is suitablyenergized to discharge an electron stream through the axial apertures.

of the annular control electrode 4 and the annuiar anode 5, thereby producing a beam of electrons which discharges through the space between the beam deflecting electrodes 6, I, l, I. The commutator ll serves as a target for receiving the electron beam, and is supported from theinsulatingdisk ll whichinturnissupported from the end wall II of the neck It having the flare ll Joined with the main wall of the tube l, the elements i2, it, It forming a reentrant end for the tube.

One pair of deflecting electrodes I, I are disposed face to face with each other on opposite sides of the tube axis, on a diameter of the tube at right angles to the diameter on which the deflecting electrodes I, 8 are disposed face to face with each other on opposite sides of the tube axis. Electrodes 8, I may be spaced slightly further along the tube axis from the cathode I than electrodes I. I.

Electrodes 3 to I are constructed and arranged as in well known cathode ray oscillographs. It is to be understood, however, that the electrodes and other parts of the tube may be varied in design in accordance with the well known technique of high frequency tubes when very high frequencies are to be utilized and in accordance with that of high power tubes when a larger amountoipoweristobeutiliaedthanwithan ordinary oscillograph tube.

The commutator electrode ll, Fig. 2, is made up of a plurality of separate electrodes II", II. II, II, If. Theseetored dish Ii, it, the ring l1 and the ring II, II have their electron receiving surfaces and their circular rims coaxial with the tube axis. The electron receiving surface of the commutator ll may be in a radial plane of the tube, or may be of slight curvature. not shown.asinthecase'oftheusual oscillograph tube screen. The commutator m y made of nickel, m'olybdenum. tungsten, or other suitable refractory metal. The disk Ii, ll and the ring it. II are divided into sections by the insulating radial gaps 28 which are on the same diameter in the Fig. 2 commutator.

While Fig. 2 shows the dish II. I. and two rings l1 and II, II. it will be understood that in its simplest form. the commutator may utiline only two rings l1 and I8, is wlthoutthe disk ormayutiliseonlyonsring i'landthedisk II, it without the other ring II. II. or may utilize only theldisk ll. ll. Furthermore. the commutator it may include additional rings around those shown in Fig. 2. as shown diagrammatically in Fig. 6, for example, in which the added rings II and ii, 22 are provided. Starting with the rim of the sectored disk ll, it which for convenience of description may be referred to as a ring, and going radially outward, it will be noted arose-rs that one set of alternate rings consisting of the rim of dish II, It. ring II, II, and ring Ii, 28,

Fig. 6 are divided by gaps II into sections, while.

the intervening rings I! and Il, constituting the other:s'et of alternate rings, are closed without gaps Each of the adjacent edges of any two adjacent rings has teeth-like segments fl projecting radially into the space between these edges. The segments 26 have such dimensions and locations that those on one edge of a ring nest with uniform spacings between those on the adjacent edge of the adjacent ring, thus forming a single circular row of segments between each pair of adiacent rings and coaxial with the tube axis. One set of alternate segments in any one row ,connects with one ring and the other set of alternate segments connects with the adjacent ring. The edges of each ring and its segments are spaced sumciently from the edges of the adiacent ring and its segments to insulate the rings from each other.

In order to obtain uniform frequency of commutation, the segments in any one row are as nearly as possible of precisely equal width measured in a direction along an arc coaxial with the rings. and the spacings measured between adjacent segments along any such are are made as nearly as possible precisely equal to each other. Each, row preferably contains a diflerent number of segments from that of other rows. The number of segments in any row is preferably greater than that of a row of smaller diameter and less than that of a row of greater diameter.

The commutator III is supported from a disk ll Figs. 1, 3, 4, of highly refractory porcelain.

glass, or other material of suitably high me-' chanical and dielectric strength to serve as a support while heated moderately and while sub- ,iected to bombardment by an electric discharge.

Fig. 4 shows details of one of the supporting elements It for the ring section II of the commutator. similar'supports Iii are provided at other points along the ring II, II and on the othenrings at the places indicated by the small circles on the rings in Fig. 2. The concentric circles 8|, II. 33 on disk ll, Fig. 3, designate the center lines of the holes M from which the disk II, I, the ring if, and the ring II, II, respectively are supported. In order to simplify the drawing, the segments 28 of Fig. 2 are omitted from the ring section II in Fig. 4.

The support it consists of a wire parallel to the tube axis and firmly secured at one end to the ringit by passing through a hole therein and having its outer end preferably welded or riveted to the ring. The wire 30 passes freely through the tubular metal spacer 8S and the hole 34 in the disk ll. At the end of the hole 30 remote from ring", the wire as is given a sumciently sharp bend or offset 38 to hold the ring it securely in place in fixed relation with the disk II and to prevent objectionable looseness of the spacer 38 between the ring and disk.

Thedisk ll.asshowninFigs.3and4,issupported by four equally spaced stiif wires 81 paralleltothetubeaxis. Oneendofeachwirefl passes freely through a hole ll near the edge of the disk. The other end is sealed into the end wall I! of the neck It and may be employed as a lead-in wire. The short wires a, II, welded or otherwise firmly secured to the lead 81 at opposite sides ofthe dish ll. provide stops for limitlug movement of the dish axially of the tube and SEARCH ROOM for holding the disk in its proper space relation with the end wall I2 of the tube.

Wires 33, 39 are preferably separated more than the thickness of the disk II at the hole 28, so that one or both of the outer ends of the wires may be bent axially of the tube into contact with the edges of the disk to adjust the position of the disk and to hold it securely in place without causing excessive stresses therein. This arrangement provides a simple and rugged form of anchorage for the disk I I, and is particularly adapted to yield to stresses originating from thermal and other causes.

Each ring and ring section, such as section It, Fig. 4, is electrically connected with one of the lead-in supports 31 or with a separate lead-in wire III by a tie-wire 4|. Various different connections between rings and sections thereof may be made, depending upon the kind of output circuits to be employed or upon the kind of output current desired. Several specific arrangements of output circuit connections for the commutator Ill are shown in Figs. 5 to 10. The direct connections between the rings may obviously be completed within the tube by tie-wires II, Fig. 4, or may be outside of the tube.

The front surface of the commutator exposed to bombardment by the electron beam is preferably, but not necessarily, treated to reveal momentarily for visual observation, the area or path on the surface over which the beam travels. One such method is to deposit on the front surface of the disk I5, l6 and the rings l1, IS, IS, etc., a thin layer of condensed vapor of a refractory metal, such as molybdenum, in an atmosphere of low pressure inert gas, such as argon, to produce a flnely divided metal film on the surface of the commutator. Another method is to coat the front surface of the commutator with a thin film of zinc orthosilicate, commonly known as synthetic willemite.

When assembling the commutator Ill and mounting it within the tube I, the disk I5, I6 and rings I1, I8, I9, Fig. 2, are first assembled on the disk II. A tie-wire II is attached to one support wire 3|) for each commutator element. The neck I3 and flare it are as yet unattached to the main wall of the tube. The four support wires 31 and the desired number of lead-in wires 40 are sealed into the end wall II of the neck I3. The disk II, carrying the commutator elements assembled therewith, is then mounted on the supporting wires 31, the wires 38, 39 being secured in position so that the commutator may be located coaxially of the tube, the free ends of the tie-wires I being connected with the proper lead-in wires 31 and I. The neck I3 is then sealed at the flare It to the main wall of the tube I to form a reentrant end therefor, care being taken to locate the commutator and its front surface coaxially to the tube. Degasing of the elements within the tube, assembly of the other parts of the tube, and the other procedures of the usual type necessary for producing a high vacuum tube, are well understood by those skilled in the art. and need not be referred to in detail. While one specific method of supporting the commutator It has been described by way of illustration, it will be understood that various other forms of support may be employed.

The circuit connections for the tube I, Fig. 1 will now be described. A source of alternating current enemy I is provided for the heater 2 of the cathode 3. A conductor It extends from the 1 heater 2 and cathode to ground at I! which also connects with the battery 53 or other steady source of direct current energy having the adjustable voltage terminals 54, 55, 66, 51, 53, 59, Bil. Terminal 55 is in the direct connection of the battery with ground 52. Terminal 56, connecting with the anode 5, is adjusted relatively to terminal 55 to provide a suitably high positive potential relatively to ground and to the cathode 3 to attract a stream of electrons toward anode 5. Termine] 54, connecting with the control electrode 4, is adjusted to a lower potential than anode 5 and may be either positive or negative relative to cathode 3, depending upon the adjustments of the potentials of the other electrodes and the characteristics of the tube. Terminals 54 and 56 are adjusted relatively to each other to control the concentration of the beam and cross-sectional area of the beam where it strikes the commutator III.

The resistance elements 6| may be included in the leads of electrodes 4, 5, 6,1, 8, 9 to prevent undesirably large currents from flowing to these electrodes.

The transformer 65, 66 has the upper and lower terminals of its secondary coil 66 connected, respectively with the deflecting electrodes 9 and 6. The deflecting electrodes 1, 8 connect, respectively, through the condensers B1 and 68 of negligibly low impedance, with the mid-point 59 of the impedance Ill shunting the coil 66. The impedance 10 includes the branched circuit II, I2 in series with the branched circuit l3, 14. The circuit II, 12 consists of the variable resistance II in parallel with the variable condenser 12, and the circuit I3, 14 consists of the variable resistance I3 in parallel with the variable inductance I4.

The combined impedance of elements II, 12 is adjusted to be equal to that of elements I3, 14, while the ratio of the combined reactance to resistance of elements II, I! is adjusted relatively to the ratio of reactance to resistance of elements 13, 14, so that the phase angle between the voltage across the impedance II, II and the voltage across the impedance I3, 14 is 90 degrees. The single phase voltage from the transformer 65, 66 is thus converted into a two phase voltage. The phase across elements I I, 12, is impressed on the deflectors 6, I, while the phase across elements I3, 14, is impressed on deflectors 8, 9, thereby deflecting the forward end of the beam of electrons so that it rotates periodically through a circular path.

Adjustment of the terminals 51, 53, 59 oflthe battery 53, control the static potentials of the deflectors 6, I, B, 9 relatively to the anode 5 and the cathode 3, the potentials being so adjusted that the beam passes by the deflectors without being objectlonably attracted or repelled by their static potentials. A path for the static potential of deflector 6 may be traced from the terminal 51, through the resistance II in parallel with another path through elements 13, I4 and coil 66. A path for the static potential of deflector 9 may be traced from the terminal 51 through elements 13, It in parallel with another path through the resistance II and coil 66. Adjustment of terminal 53 controls the steady potential diii'erence between deflectors i, I, so that the circular path traced by the beam may be properly centered in avertical direction. In a similar manner, adjustment of terminal 58 controls the potential difference between deflectors 3, 9 and permits of centering the circular path in a horizontal direction.

'I'heclrcularpath ofthebeammaythusbeadjusted to a position coaxial with the tube and with the disk I3, II and the rings II, I3, I9, and so on, of the commutator I0. The position of the path at any instant may be observed by watching the luminous path traced by the beam on the surface of the commutator, or by observing the current passing through the respective leads or circuits connecting with the different parts of the commutator.

Referring to Figs. 1 and 5, the output circuit 80, 82 of the tube connects the commutator ring II with the adjustable positive potential terminal 60 of the battery 53, and includes the output coupling ll, 02, consisting of the variable tuning condenser II in parallel with the inductance 02. The coupling ll, 82 may be tuned to resonance with the frequency of the desired output wave. Coupled with the inductance 32, is the inductance 03, connected with the utilization circuit 04, labelled U0.

The output conductor 05 connects with the right hand sector l8 of the disk IS, IS, and the right hand sector I! of the ring III, I! and extends by way of the lower contact of the switch blade 06, when the two pole switch 06, 81 is in its lower position, to the cathode 09 of the current limiting device 90, having the anode from which the path of the output current may be traced to the resonantfrequency determining circuit 02, 93, consisting of the inductance coil 82 in parallel with the variable tuning condenser 03, and through the lower contact of switch blade 81. to conductor and 62 to the battery 53.

The current limiter 00 may be a rectifier of the well known thermionic diode type, having its cathode heated to such a temperature by current from the battery 48 controlled by the variable resistance 30 that the space current increases rapidly with increase of the positive potential of the anode relatively to the cathode of the rectifier, but the space current quickly reaches a substantially constant predetermined strength or value which does not increase appreciably when the anode-cathode voltage of the rectifier increases further to considerably greater values corresponding with the maximum working voltages applied thereto. In other words the rectifier 90 becomes saturated at a voltage which is low compared with the usual maximum instantaneous operating voltages applied thereto. The rectifier 00 thus prevents the amplitude of the current supplied to the frequency determining circuit 92, 03 from departing from a predetermined value.

The resonant circuit 92, 03 is preferably of lowloss construction and is preferably sharply tuned. The circuit is also preferably arranged in well known manner to maintain its constants unchanged when the temperature in the vicinity thereof changes. Adjustment of the tuning is therefore primarily under the control of the variable condenser 03.

The left hand sector II of the disk II, It and the left hand sector I0 oi the ring II, I9 are connected together with the conductor 06, in series with the variable resistance 31, the choke coil 00, and the conductor 02, connecting with the positive terminal 33 of the battery I3. Resistance 01 is adjusted to prevent an undesirably large current through the conductor 30. The choke coil 00 is of high impedance to alternating current of the deflection frequency or higher. a

The inductance coil 00, variably coupled as a transformer secondary with the inductance coil 02, has its upper terminal connected through the adjustable phase controlling reactance I00, the

conductor It, the upper contact 01' the switch I02, and the rheostat I03 in series, to the upper end of the potentiometer I04. The lower terminal of the coil 09 connects through the conductor I05 and the upper contact of the switch I06 with the lower end of the potentiometer I04. Two or more sliding contacts IN on the potentiometer I04, each connecting,respective1y, through one of the variable phase shifting reactances I00 and with one of the contacts of the sliding switch I00, provide a connection between the potentiometer I04 and the upper end of the primary coil 60. The lower end of the potentiometer connects directly with the lower end of the coil 65.

The repeater or amplifier IIO, labelled A, and adapted to repeat in the direction indicated by the arrow, has its input terminals II I, II2 connected across the conductors IOI, I05, and its output terminals Ill, Ill connected respectively, with the lower contacts of the two-pole switch I02, I05. The amplifier A may be of any well known type, adapted faithfully to reproduce at its output terminals, the wave impressed upon its input terminals, without introducing distortion.

The form of amplifier shown in the drawing is of the well known resistance-capacity coupled type, in which the low impedance blocking condenser IIG in series with the potentiometer resistance H6, is connected across the input terminals II I, II2, the sliding contact III for varying the amplification, being connected with the grid of the triode repeater or amplifier tube I I0. The usual direct current source 8 is provided to polarize the grid negatively with respect to the cathode for the purpose of reducing distortion. The anode-cathode circuit includes the resistance I20 in series with the source of space current I2I, and transmits output waves through the low impedance blocking condenser I22 to the output terminals H3, III which are connected with the lower contacts of the switch I02, I06, in such phase as to provide the same instantaneous polarity for the potentiometer I04 as the upper contacts of the switch I02, I06. The amplifier A may obviously consist of more than the one stage shown.

The repeater or amplifier I25, having its input terminals connected in parallel with those of the repeater I I0, serves as unilateral transmission device to transmit waves of the frequency selected by the tuned circuit 92, 93 to .the, utilization circuit I2 and to prevent reaction of the circuit I26 on the tuned circuit 92, 93.

The independent source of waves I30, is connected across the upper contacts of the switch 08, 81, so that when the switch is in its upper position, impulses are transmitted from the source I30, through the rectifier 90 to the resonant circuit 92, 03, in place of impulses transmitted over conductors 05, 05 from the commutator I0. In this case the circuit 02, 93 is preferably tuned to the frequency of the source I30, but may be tuned to a harmonic thereof. I

When operating the tube I, the adjustable terminal 60 of the battery 53 is adjusted to such a positive potential relatively to the cathode 3 that the beam of electrons discharges on the commutator I0. The focus of the beam may be adjusted by varying the potentials of electrodes 4, I. The static potentials of the deflectors 6, I, I, 0 are adjusted. by terminals 01, 58, 09, as already referred to, so that the beam is suitably centered relatively to the commutator axis.

The current in the beam, builds up almost individing its becauseofthebeambeingdirectedwhollyor pcrtupcmsector iineartheoenterofthedisk II, is, an im of direct current derived from the battery II by way of cathode I. discharges through the conductor 8!, the current limiter O0 and the resonant circuit 92, ll, back through the conductor OI to battery 68. Waves oi resonant frequency are thus set up and stored in the irequency determining circuit or, 98. and are transmitted from the secondary coil 89 of the coupling II, 00. through conductors III, III. switch III, I" to the potentiometer ill. from which the waves are transmitted through the transformer 6!, It and to the deflectors l. I. 8. I, causingthebeamtobedeflectedcyclicaily over acircular path which quickly increases in diameter to a fixed steady state value of constant frequency as impulses are supplied to the circuit l2, it in successive cycles.

For the production of the highest frequencies, the switch m is placed in its highest position with the highest slider lll'i near to but somewhat short or itshighest possible position. The resistance Ill is then adjusted until the control wave applied to the deflectors l, I, I, I. has suflicient amplitude to cause the beam to trace a path over the outermost row ofsegments I1, .19. Figs. 2

- and 5. The uppermost phase shifting reactance ill may then be adjusted to establish the optimum output of waves oi the deflection frequency, so that the beam strikes and removes from the ring section I! at such instants of time that successive impulses oi the deflection frequency pro duce the desired additive effect in the circuit 0!,

It. or provide the desired stability of operation.

Adjustment of the resistance in may be necessary while adjusting the phase shitting reactance Ill. in order to. maintain the control wave at its proper amplitude, so that the beam maybe kept traveling over the Proper row i1, II, II.- One half of one set of alternateseg'ments, namely those on the edge of the sector I. collect direct current during every other half cycle of the deflection wave. At the beginning of one half cycle, the beam passes from ring section ll to section I9, and for that half cycle the resonant circuit s2, 9! is supplied with a series of direct current impulses corresponding with the number of segments over which the beam passes. These impulses are integrated on the condenser ll, producing an eil'ect on the circuit I2, 83 similar to that of a single direct current impulse of a duration of one half a cycle oi the deflection wave.

a At the end of this first half cycle, the beam passes from the ring section I! to section ll andtransmits direct current to the section II during the second half cycle without transmitting any current to the circuit 82; as. Succeeding cycles repeat the periormance of the flrst cycle. The beam thus commutates direct current at the deflection irequency and thereby supplies the necessary control current to maintain the cyclic defleccurrent abruptly, beam on the segments.

multiple thereof may be selected by on to the utilization circuit N, to the exclusion of wave energy of other frequencies. By making the on characteristic of the elements ll, 82, ll sumciently broad, several different frequencies may be transmitted to the circuit ll without changing the impedance adjustment or these elements. when the range of output frequencies is very wide. it is preferable to substitute appropriate reactance and coupling elements II. or, II for different portions or the frequency range.

The coupling 9!, as is preferably made loose enough' to insure resonant circuit O2, 98 at the one desired fre 'quency, and to insure the desired constancy of the output frequency. when .the uppermost slider llll is near the upper end of the resistance .llll and the resistance "3'18 adjusted to a minimum. and the energy supplied through the secondary coil II to the deflectors b, I, l. I, is insuflicient to maintain the desired diameter of circular path of the beam. some increase in energy may be obtained by the expedient of increasing the coupling 82. $9, or by raising the saturation limit of rectifier ill. or by both at these expedients. However. when these expedients are inadequate or are not desired, use may be made of the amplifler III by connecting the switch I02, I" in its'lower position, and adjusting the slider III until the amplifier ill provides the desired amount of amplification.

The second and third contacts from the top in the switch m, in the order named, provide voltages of successive'lower strength or value for the deflectors I, I, U, I from the second and third sliders ill, respectively of the potentiometer llll. When the switch II! is in its second from the top, the associated or second slider It! is adjusted to make the beam trace its path over the row", is, H to produce in the output circuit so. impulses and waves of a frequency equal to thedeflectiou frequency multiplied by one-half the number of segments in the row. When the switch III is in its third position. the thirdslider llllisadjustedtomakethebeam travel wholly over the sectors II, is. which serve as a two segment commutator to produce waves of the deflection frequency in the utilisation circult i2! and on the deflectors I. I, 0, I; By transferring the switch ill from second to third positionJtwiIIbeseenthatoutputcm-rentenergy ceases to be transmitted to the output circuit II. For each position of the switch II. andof stability of operation or the CROSS KLrtKtNUI:

the associated slider ill. the associated phase shifting reactance Ill is adJusted-to give the deflector control circuit as a whole, the desired phase angle. as described above in connection withthe adiustmentoftheflrstorumlcrmoet reactance Ill. During the adjustment of the circuits of the second and third contacts of switch I", the resistance"; remains unchanged. It isnowpossibletoshiftthepathoftheheam quickly from one row of segments to another and thus select by the switch Ill, .any one of several difl'erent frequencies for production without changing the tuning of the resonant frequency determining circuit II, 88.

Since the circuit ii, I! does not control the frequency of commutation. the tuning thereof need not be as critical as that of the circuit 0!, I]. and the circuit Ii, I! may therefore be of relatively low cost construction for its particular frequency range.

In order to obtain an output frequency in the range between two adjacent communication frequencies, one of the commutation frequencies. below that of the upper of these two adjacent frequencies. may be employed to produce a harmonic havingthedesiredfrequency,orthedesiredfretion frequency sufliciently to produce the desired commutation or harmonic when changing the tuning of the circuit 0!. 08, any

tendencyof'thepathofthebeamtobecomenom commutation frequency to a frequency many times that of the highest commutation frequency. Because of the fact that the frequency range of adjustment of the circuit 02, It may ordinarily bequitelimitedandinsomecasesresonancemay be permanently flxed ata single frequency. the control circuit elements including the transformer elements I, it and II, I. and the impedance elements 10, are adapted for-use without replacement while the output frequency is varied from its lower to its upper limit. 4

More than three contact positions may obviously be provided for the switch I00, together with the associated elements I01, ill, when more than three rows of commutator segments are provided. as in Fig. 6. When rows of successively larger diameter contain respectively larger numbers of segments, the successively higher positions of the switch I" select successively higher commutation frequencies -for production. but in aybemadesufring I! would have 100 segments in that row and the beam current would be commutated at a frequency at or 100 I, thereby producing direct current impulses and waves of a frequency of 100 I. The tenth harmonic of the fundamental frequency of would have a frequency of 1000 I lntheassumedcase. Ifitbefurtherassumed that the deflection frequency determining circuit 02, I! is made resonant to an audio frequency wave of 1000 cycles, the current would be commutated at a frequency of 100,000 cycles and the tenth harmonic would be 1,000,000 cycles.

Itwillbeunderstoodthat thenumberofsecmentsinanyonerowmaybegreaterorlessthan 200 and that the frequency, is at which circuit II, II is resonant may be subaudihle, or may be a be made to commutate, not only at very low frequencies, but aho at extremely high frequencies. and toproduce directcurrentimpulsesorwaves when the number of lecmentsisconsiderablyless than200in-onerow,

oyingahighdeilectionfrequency.

isnecessarytousegreatcarelnavoidaminimumJndtheimpedancesatthecow nandatthecircuitterminaticnsshmiidbe tched for emeient operation. Balanced cirts,

owndiagrammaticallyinmmoandmand ate veryhighi'requenciaaretohepro- WSEARCH BOOM veryhighfrequenciesmayheproducedbyem contact of the blade "I of the two-pole two-' position switch ill, ill. Sectors- II. II and II are connected with the lower contact of the switch blade I and with the upper contact of the switch blade ill. Sectors I0, I! and 22 are connected with the deflection control circuit conductor 85. The switch blade ill provides an output circuit path through the variable noninductive resistance coupling element I" to the positive conductor 02 of the battery II. The low impedance blocking condensers m, I are connected to transmit impulses, representing the potentialdiiferenceacroaresistanoellhtothe utilization circuit, UC, Ill, by way of the upper contact of the switch Ill. The conductor Ill. extending from condenser Ill to circuit Ill is grounded at ill.

An amplifler A, Ill. has its input connected between the condensers Ill, Ill, and its output connected at one terminal to the lower contact of the switch I48 and at the other terminal to conductor Ill'. When switch Ill is in its lower position, the amplifier Ill is inserted between coupling 2 and circuit Ilt to supply amplified impulses to circuit Ill and to isolate circuits connected with the amplifier output from the coupling circuit "2. Condensers Ill and Ill in conjunction with the ground Ill isolate and safeguard the utilization circuit ll! from static or non-impulsive potentials from the battery 63.

The switch blade Ill, when in its upper position, connects the output circuit resistance Ill with the closed rings II and II, so that when the beam is deflected over any desired one ofthe four rows of segments connected with rings I1 and 20, impulses of the corresponding commutation frequency with harmonics thereof are transmitted to the utilization circuit I". It is thus possible to select any one of a plurality of output frequencies by the switch I, Fig. 1 while using only a single frequency determining circult .2, SI, which may be tuned much lower than the output frequency and whose tuning may remain unchanged while the output wave is shifted to any one of several different commuta tion frequencies extending over a wide range.

If desired, the switch IIII may be closed to connect the resonant circuit iii, m, including theinductance III and the variable capacity Ill, across the utilization circuit lli, so that some one of the frequency components of the output wave may 'beselected for transmission to the circuit Illto the exclusion of all components of different frequency.

In its upper position, the switch blade Ill discharges direct current from the sectors Ii, II and II of the commutator. and in its lower position from rings l1 and III. The direct current path from the blade Ili may be traced through the variable resistance 01, the high impedance choke 0011 It and conductor If to the battery It.

When the switch blade llIl is in its lower position. the sectors I, I8 and 2! of the commutator are connected with the output resistance coupling Ill. Two different commutation frequencies are thus supplied simultaneously to the output circuit, one being the deflection frequency and the other being at a higher frequency deter- .mined by the rate of travel of the beam over a particular row. of segments. The frequency range obtainable with this connection, therefore extends from the lowest deflection frequency to the highest harmonic of the highest commutation frequency. Furthermore, when the output circuit has a broad frequency transmission characteristic, as when the switch Iill remains open and the utilization circuit Il! is not sharply selective, the resulting wave transmitted to the utilization circuit consists of a band of components of different harmonic frequencies, including the fundamental. Since the direct current impulses are cut off during one-half of each successive cycle of the deflection frequency, while the beam is impinging on one of the sectors It. It, 22, the output wave band is modulated at the deflection frequency.

The Fig. circuit shows how the Fig. 5 circuit may be expanded by adding extra rings to the commutator,asin1"ig.6. l'nadditiontotbe output circuit II, If, connected with the ring Il, Pig. 5, there is provided in I, an output cuit I". 02, connected with the ring fl. output coupling III, an, included in the output beam is selected by the switch III, as already described, so that the beam is deflected over the desired row of segments.

It may be assumed that the row II, ll, ll contains 211: segments and that the rows of successively larger diameter contain, respectively, 2n, 2p and 2:; segments. The output coupling II, I! may then receive impulses having a commutation frequency of either ml or a}, depending on whether the beam traverses the inner or outer row of segments of the ring II, the deflection frequency being represented by 1. Similarly, when the beam travels over the inner or outer row, respectively, of the ring IO. impulses having a commutation frequency of p! or of. respectively, are transmitted to the output coupling III. I62. Circuits-II, II and Ill, Ill are preferably tuned, to the frequency of the desired waves, which may be either a commutation frequency or a harmonic thereof, but if desired these circuits may be adjusted to have broad frequency transmission characteristics to permit of the simultaneous transmission of two or more components of difl'erent frequency.

The output channel ll, ll. l2, ll, or the output channel Ill, Ill, I", Ill, may be selected to be energized by output waves, or to be deenergized. by merely operating the switch III to shift and to confine the transmission of waves to the output channel I5, I26. It will be understood that the waves transmitted to the different channels ll, Ill and I26 may each be of a different frequency when their respective commutation frequencies arediflerent, or may be of the same frequency when their respective commutation frequencies are the same.

Fig. 8 shows aeommutator Ill and connected circuits adapted for substitution in Fig. l in place of the Fig. 5 arrangement. The Fig. 8 arrangement is particularly adapted for producing ultra-high frequency impulses and waves, al-. though it may also be employed for producing impulses of any lower frequency. The central disk "I, I12 differs from the disk II, I, Fig. 5, merely in having one sector III larger in angular measure than the other sector Ill. The ring I1 surrounding the central disk, as in Fig. 6, has segments on its edge fitting between alternate segments on the circular rim of the disk I'll, I12, as described in detail in connection with the ring I! and disk I5, ll, Fig. 2. The small sector I'll may have one or more segments on its edge, depending upon the angular widths of the sector and of the segments.

The balanced U-shaped coupling circuit I'll, I'll, has one free end of the U connected with the ring I! and the other free end connected with the larger sector I'll. Length varying means, such as the U-shaped slides I", are provided in eacharm of the U-circuit I18, Ill to adiust the wave length or tuning and the balance of the circuit at the desired commutation or harmonic frequency. The middle point of the base of the U of the circuit I'll, I", is connected with the positive potential direct current. supply lead 6!. The smaller sector I12 connects with the deflection controlconductor ll. Impulses of direct current, representing commutation at the deflection frequency, are collected on the sector "I and transmitted over the conductor 85 to the circuit 02, 91. Fig. l. The utilization circuit U0. I'll, is connected through the low impedance blocking condensers III, III. with the variable coupling points III, III, near the base of the U of the outputcoupling I13. I14. Waves of the desired commutation or harmonic frequency. for which the coupling I13, I'll is adiusted, are transmitted to the utilization circuit I".

By reducing the angular width of the sector "2 as much as possible, in terms of the number of segments thereon, the sector I'll and the number of segments thereon may be made correspondingly larger, so that the duration of the interruption of the train of impulses while thebeam is on the segment or segments of the sector III, is correspondingly minimized.

Fig. 9 shows a commutator II and connected circuits adapted for substitution in Fig. 1 in place of the Fig. 5 arrangement The ring il surrounds the equal sectors II, it, as in Fig. 2. The circuit is similar to that of'l lg. 8, except for the portions of the coupling circuits within'the' rectangle C. The portion of the coupling cir cult within the rectangle 0, includes in each arm I13, I", a lumped variable tuning capacity I" in parallel with a lumped inductance I which take the place of the distributed capacity I and inductance .in the corresponding arms in, I'll in Fig. 8. The junction oi the two seats of elements III, I", Fig. 9, connects with the positive direct current supply lead It. The inductance I81. coupled with the inductances I86, I". connects with the utilization circuit UC, I" andtransmits waves of the selected output frequency thereto.

Each circuit I, I is preferably tuned to the same desired output frequency which may be either the commutation frequency or a harmonic thereof. The Fig. 9 clrcuitC is intended more particularly for use at lower frequencies than the Fig. 8- circuit C, but it is to be understoodthat the circuitsC'ofml- Oandilmaybe interchanged to adapt the Fig. 8 gement for the production of lower frmuencies or the Fig. 9 arrangement for the production of higher frequencies. i

Fig. 10 shows a commutator i and its connected circuits for substitution in Fig. 1 in place of the Fig. 5 arrangement; While the arrangements of Figs. 5, ,8, '1, 8 and 9 are adapted for either self excitation or separate excitation by the independent source I. Fig. 1, the Fig. 10 arrangement is adapted only for separate excitation. The switch It. II, is placed in its upper position, Fig. 1. so that waves 'from the source ill supply a train of direct current impulses to the resonant circuit .2, ll. by rectification in the rectifier N, the circuit 02, 83 being tuned to the frequency of the source I" or to a harmonic thereof. The rectifier I. limits the amplitude of the impulses and the excitation ofthe' circuit l2, 03, thus maintaining the amplitude of the control waves supplied to the deflectors I. I, I. I substantially constant. so that the deilee tions of the beam are kept in their predeteriki cR0ss REFERENCE 'flelds of the two sets of deflecting electrodes mined ath when fluctuations of the at... m tentg to make the beam depart from its desired pa The commutator I has the central disk liftand the coastal rings It! and I having 5 meals on their adjacent circular edges. as described with reference to the segments on the circular edges of the disk "fit, the ring ii and the ring it, ll, Fig. 2. The switch I". Fig. l,

is positioned to select the desired row of scg 1o ments to be traversed by the beam. when the row ill. m is selected and the switch ltll is in its upper position, a continuous train of impulses are transmitted to the two output conductors Ill and the coupling circuit C which may be like the circuit C of either Fig. 8 or Fig. 9. The resulting waves are transmitted from the circuit C to the utilization circuit I'll. When the row "I. II! is selected by the switch ill, the switch I is placed in its lower position to connect with the disk "I, so that the output conductors i" receive impulses from the seg- .ments in the row ill, I.

Thetsofl 'lgaihlandlilare similarinhavlns balancedcircuitsand inbeing operablein push-pull relation in which on the average more than one impulse is received during each commutation cycle or the output wave above the deflection frequency. whereas the arrangements of Figs. i5, 6, and I are of simpler construction without balancing of the kind used in the arrangements of Figs. 8, 0, and i0, and

- the output circuits of Figs. 5, e, and 1 receive only one impulse during each commutation cycle of the output wave above the deiiection frequency.

In the arrangement of any of the above described figures, the beam or electric carriers may consist of carriers other thanelectrons per se, since the desired relation of the focus to the commutator, and the deflection and commute tion of the beam may be obtained wlth a' beam of electric carriers other than simple electrons. Furthermore, one or both of the two electrostatic I, I, and I, 9, may be replaced in well known manner by magnetic fields, adapted to produce the cyclic deflection of the beam.

Any number of rows of segments may be providedinthecommutatorofany oftheabovedescribed figures. one row or the minimum number of rows being preferable to a larger number of rows when electrostatic capacity across the outputcircuitis tobeminimised, asinthecaseof the production of very high frequencies.

A circular path of deflection'of the beam has been described and is preferred for many purposes, since it is easier to construct a commutator having sumciently accurate dimensions and the output frequency is less likely to be variable when. the path is circular. Many of the features of the invention may be employed, however, when the cyclic path traced by the beam is of some other shape than circular. It will be seen that the circular path is merely one species of an ellipsoidal path, and that another species of the ellipsoidal path is a linear path. In any case where uniform frequency isdesired. any one segmentinaglvenrowshouldbeofmchlength along the path traced by the beam-relative to 70 SEARCH ROOM The angular measure of the sectors II, it, or II, IO, or 2|, 2! of Figs. 5,5, 7, and 9, may be made unequal in the manner shown by the unequal sectors ill. I12, Fig. 8, and may have any other relative angular measure, provided there is a diiference between the number of impulses transmitted to the circuit 91. 98 in successive half cycles of the deflection control frequency to which the circuit 92. 93 is tuned. Viewed from another aspect. the deflection frequency may be supplied to the circuit 91, 91, if the impulses transmitted thereto are derived from less than all of one set of alternate segments in the row.

When the source of energy 53 is adjusted to vary the output energy, or when the source 53 departs from its desired potential, or when certain other changes such as load and impedance variations occur in the circuit, the amplitude limiting device 90 tends to stabilize the operation of the system at the desired commutation frequency, so that the beam is kept directed over the desired row of segments.

When commutating the beam current to produce impulses of a desired frequency higher than twice the deflection frequency, the production of impulses of unwanted lower frequencies is avoided within the range between the deflection frequency andthe desired higher impulse frequency, in contrast with the production of such lower frequency impulses in systems utilizing a plurality of small harmonic producing stagesin cascade. Losses incident to the production of these intermediate frequencies may thus be avoided, and the impulses of desired frequency, produced in accordance with the present invention, may. at the same time be of greater energy for a given input energy than in such a cascade system.

What is claimed is:

l. The method of producing electric impulses, which comprises producing a space discharge in the form of a beam of electric carriers, periodicaily deflecting said beam over any chosen one of a plurality of predetermined paths. causing the deflecting beam to commutate electric current in said chosen path at a predetermined frequency, and utilizing the beam simultaneously to commutate current at a different predetermined frequency.

.2. The method which comprises producing a space discharge in the form of a beam of electric carriers, utilizing a control wave of predetermined frequency for periodically deflecting the beam, utilizing the deflecting beam tocommutate current at a frequency higher than that of the positive and negative peaks of said control wave. and deriving said control wave from said deflecting beam.

3. The method which comprises producing a space discharge in the form of a beam of electric carriers, utilizing a control wave of predetermined frequency for rotating one end of the beam over a predetermined path. utilizing the rotating beam to commutate current at a frequency higher than that of the positive and negative said commutatedcurrent a wave of frequency lower than said predetermined frequency. and

utilizing said lower frequency wave to produce quency, which comprises producing a beam of electric carriers. periodically deflecting the beams and utilizing the deflecting beam to transmit current by commutation simultaneously to each of said circuits at a frequency of commutation in each respective circuit equal to the frequency for which'the circuit is selective.

6. The method of transmitting waves to a plurality of circuits, each selective to a different frequency. which comprises producing a beam of electric carriers, periodically deflecting the beam. utilizing the deflecting beam to transmit current by commutation simultaneously to each of said circuits at a frequency of commutation in a first of said circuits equal to the frequency for which said circuit is selective and at a frequency of commutation in a second of said circuits which is a submultiple of the frequency for which said second circuit is selective.

'1. The method of transmitting waves to a plurality of circuits, each selective to a diflerent frequency, which comprises producing a beam of electric carriers, periodically deflecting the beam. utilizing the deflecting beam to transmit current by commutation simultaneously to each of said circuits at a frequency of commutation in each respective circuit equal to the frequency for which the circuit is selective. and utilizing the current commutated at one of said frequencies toproduce the periodic deflections of the beam.

8. The method which comprises producing a space discharge in the form of a beam of electric carriers, periodically deflecting the beam. deriving a series of electric impulses from the beam during a portion of each cycle of deflection of the beam, the impulses in each series having a predetermined frequency, converting said impulses into a wave of frequency lower than said predetermined frequency, and utilizing said lower frequency wave to periodically deflect the beam.

9. In combination with a plurality of circuits, each selective to a diflerent frequency, means for producing a beam of electric carriers when suitably energized, means responsive to an electric wave for periodically deflecting the beam, and means including a commutator for transmitting current simultaneously to each of said circuits from the deflecting beam at a frequency of commutation in each respective circuit equal to the frequency for which the circuit is selective.

10. In combination with a plurality of selective circuits, means for producing a beam of electric carriers when suitably energized, means responsive to an electric wave for periodically deflecting the beam, means including a commutator for transmitting current simultaneously to said circuits from the deflecting beam at difl'erent frequencies of cbmmutation, one of said circuits being selective to current commutated at one of said frequencies, and another of said circuits being selective to a harmonic of one of said frequencies at which commutation takes place but non-selective at all said commutation frequencies.

11. In combination, a space discharge device having means for producing a beam of electric carriers when suitably energized, an input circuit for periodically deflecting the beam in response to current of predetermined frequency, an, output circuit, means including a commutator whereby the deflecting beam commutates current at a frequency higher than that of the positive and negacsoss RtitRENCE tive peaks of said deflecting current and whereby said commutated current is transmitted to said output circuit, said output circuit being selective to a component of said higher frequency current, a frequency determining element selective to said predetermined frequency and coupled with said input circuit, and means for deriving impulses of said predetermined frequency from said deflecting beam and for transmitting said impulses to said frequency determining element.

12. In combination. a space discharge device having means for producing a beam of electric carriers when suitably energized. means responsive to a periodic current for deflecting the beam. means including a commutator.for deriving from the deflecting beam a current commutated at predetermined frequency. means for deriving from said commutated current a current of frequency lower than said predetermined frequency, and means for transmitting said current of lower frequency to said deflecting means.

13. In combination, a space discharge device having means for producing a beam of electric carriers when suitably energized. means responsive to an electric wavefor periodically deflecting the beam, means for deriving a series of electric impulses from the beam during a portion of each cycle of deflection of the beam, the impulses in each series having a predetermined frequency, means for converting said impulses into a wave of frequency lower than said predetermined frequency, and meansfor transmitting said lower frequency wave to said deflecting means.

14. In combination, a space discharge device having means for producing a beam of electric carriers when suitably energised, means responsive to an electric wave for periodically deflecting the beam, means for deriving electric impulses of predetermined frequency from the deflecting beam and for utilizing said impulses, means for deriving another set of impulses of said frequency from the beam during a portion of each cycle of deflection of the beam, means for converting said last mentioned impulses into a wave of frequency lower than said predetermined frequency. and means for transmitting said lower frequency wave to said deflecting means.

it. In a wave producer, a space discharge device having means for producing a beam of electric carriers when suitably energized, control means adapted to be energised to periodically deflect the beam over a predetermined path, an output circuit. means for periodically collecting a component of energy from the beam at one frequency and for transmitting said component to said control means, and means for periodically collecting another component of energy from the beam at a higher frequency and for transmitting said higher frequency component to said output circuit.

16. In a wave transmission system, a space discharge device having means for producing a beam of electric carriers when suitably energised, control meanaadapted to be energized to periodically deflect the beam over a predetermined path, a plurality of output couplings, a commutator having segments disposed in the path of the deflecting beam, one of said output coupling being connected with one set of alternate segments of said commutator, and another of said output couplings being connected with less than all of one set of alternate segments of said commutator.

17. In a wave transmission system, a space discharge device having means for producing a beam of electric carriers when suitablyenergized,

angers control means adapted to be energised to periodically deflect the beam over a predetermined path, a plurality of output couplings, a commutator having segments disposed in the path of the defleeting beam. one of said output couplings being connected with one set of alternate segments of said commutator, another of said output couplings being connected with less than all of one set of alternate segments of said commutator. and means for transmitting current from said last mentioned output coupling to said control means for maintaining the periodic deflection of the beam.

18. In a wave producer; a space discharge device having means for producing a beam of electric carriers when suitably energized, a commutator having segments, a controller responsive to alternating current for periodically deflecting the beam over said segments. a flrst output circuit connected with certain of said segments, means for transmitting control impulses from said output circuit to said controller, and a second output circuit differently connected with certain of said segments for receiving impulses of a frequency differing from the frequency of deflection of said beam 19. In a wave transmission system, a space discharge device having means for producing a beam of electric carriers when suitably energized, a commutator having a plurality of rows of segments, control means adapted to be energized to periodically deflect the beam over any one of said rows, output connections for said segments, means for selectively determining the row of segments over which the beam is to be deflected, and means responsive to energy to be transmitted to said control means for maintaining the deflections of the beam over said selected'row when fluctua tions of said energy tend to make the deflections depart from said selected row.

20. In a wave producer, a space discharge device having means for producing a beam of electric carriers when suitably energized. said device having a beam deflecting circuit and having an output circuit through which current from the beam is periodically transmitted, said output circuit having a coupling with said deflecting circuit. and means responsive to the beam current periodically transmitted through said output circuit for preventing the wave transmitted through said coupling to the deflecting circuit from departing from a predetermined amplitude.

21. In a wave transmission system, a space discharge device having means for producing a beam of electric carriers when suitably energised, a

I commutator having a row of segments, control means adapted to be energized by a wave for periodically deflecting the beam over said row of segments, and means responsive to the wave to be impressed on said control means for preventing the amplitude of said wave from departing from a predetermined value.

22. The method of translating electric waves which comprises producing impulses, preventing said impulses from departing from a predetermined amplitude, storing said impulses by resonance, controlling the deflections of a beam of electric carriers in accordance with the resulting resonant waves. and commutating direct current under the control of the deflections of the beam.

SEARCH BOOM 23. The method which comprises producing a space discharge current, periodically deflecting the space discharge current, storing energy in the form of waves under the control of said deflected may): 1 1

charuedevleehevlnlmeeutorwoducincabeem of electric curlers when nfltebl! energised. e commutator having e row 01 secmenm'outw connectlonliorealdsecmentmmeensedaptedto heenercisedbyanelecfl'lccurrenttoeeuethe 'beemtobeperlodicallydeflectedlnapredeterminedpethcversaidmwotsegmenmsndmeam for melntainin: the deflections otthebeamwithin said ed path when fluctuations oi the mum: current tend to make the beam traceadlfierentpeth.

JUS'I'IIILI'IARING.

CERTIFICATE OF CORRECTION. Patent No. 2,12h,973. July 26, 1958.

JUSTIN L FEARING It ichereby certified that error eppeare in the printed specification of the above nmbered patent requiring correction as follows: Page 5, first column, line 61, forDegasing reed Degaesing; page 5, second column, line 22, for the word "by" road for; page 6, first colmin, line 22, for communication" read comnutationg second column, line 52, for "attention" read attenuation; page 8, first column, line 39, for "seats rend sets; and that the said Letters Patent should be read with this correction therein that the same may confom to the record of the case in the Patent Office.

Signed and. sealed an; 15th day of September, A. n. 19 8.

Henry Van Aredale Acting Commissioner of Patents.

woducincabeam mm dlecharle heenercisedhyanelecmocurrenttccauethe 5 tormcflmmlsemweventin said predetermined path when fluctuations oi 2.10am being stored from depart-inc man a predetercharadevioehavlnameautor minedvamcandoontrollingaaidpenodicdefleeoielectrlccan'ienwhen nfltabl! tionsinaccm-daneewlthlaidstoredwavee. having a row at fli'i'hemethodotwoducmlelectflewavee connectlonliorcaldsecmen currentperiodlcalb heemtobeperledicallydeflectedlnapredeterof sald currentinthe minedpethcversaidmwotsegmenmandmeam in: the amplitude 01 saidlmmflseetrom depth for malntaininc the deflections ottheheamwithvaluesto io r nun-0%. theenercmnccurrenttendtomaketheheam w control traoeadlfierentpath.

JUS'I'III l5. FEAR-1N0.

dnerlodiclmpullee thnproductlmotsal 25. mawavetrannnllllonmtemmspecedle- CERTIFICATE OF CORRECTION.

July 26 1958.

It iihereby certified that error appears in the printed specification of the above nmbered patent requiring correction as follows: Page 5, first column, line 61, forDegasing read Degassing; page 5, second column, line 22, for the word "by" road for; page 6, first colmn, line 22, for communication" read commutation; second column, line 52, for "attention" read attenuation; page 8, first column, line 39, for "seats read sets; and that the said Letters Patent should be read with this correction therein that the same may confom to the record of the case in the Patent Office.

Signed and. sealed an; 15th day of September, A. n. 19 8.

Henry Van Aredale Acting Commissioner of Patents.

Seal 

